Christmas dinner is traditionally based around produce which is available fresh in this country in the middle of winter.

But just as Britain's climate is changing, so are its crops - at least if two of yesterday's most exotic home-grown menus are anything to go by.

In Exeter, John and Marjorie Parker tucked into a salad made from newly-picked tomatoes grown outside their bathroom window.

Meanwhile in Canterbury, June Millar was working out how to incorporate bananas more suited to the islands of the Caribbean where she grew up.

Both are just the latest examples of how nature has been turned upside down by what is set to be the hottest year since records began.

It was appropriate, then, that yesterday was more grey than white - in fact one bookmaker is offering odds of 50/1 that there won't be a white Christmas before 2050.

Mrs Parker, whose husband is a retired farmer, said she was stunned when her vines continued producing juicy, ripe tomatoes three months later than usual despite being almost completely open to the elements.

"I have never known tomatoes so late in the year - and they are delicious, too, not like the bland ones you get in supermarkets," said the 77-year-old. "We had them with a nice bit of cheese after our Christmas dinner."

She planted the tomatoes, from the variety Gardeners' Delight, in April, and apart from a plastic cover for the first few weeks and some fleece to protect them from the first frosts, they have been in the open air throughout.

They first bore fruit in July and haven't stopped since, to the extent that the couple pulled the vines up just before Christmas to stop them sprouting.

"We just couldn't take any more tomatoes - they were growing faster than we could eat them," said Mrs Parker.

Two hundred miles to the east, something even more exotic was going on thanks to 61-year-old Mrs Millar's attempts to replicate in Kent the tropical gardens she experienced growing up in Trinidad.

With nothing more than her home's suntrap qualities, she has managed a crop of bananas - albeit stubby and slightly green - and a solitary pineapple.

So after picking them last week, Christmas dinner for she and husband Chris featured the novel elements of banana fritters, pineapple chunks on cocktail sticks, and banoffee pie - all from home-grown produce.

"I grew up in Trinidad and thought it would be nice to try and recreate that tropical scene in our garden, and started to grow a range of exotic plants," Mrs Millar said yesterday.

"I have six banana trees, bamboo plants, palms, lemon and pineapple trees, and some beautiful bougainvillea flowers, but this is the first year the trees have grown actual bananas.

"I think everything has grown so well because of the warm weather this year and the fact my garden is a suntrap."

Rob Brett, glasshouse manager at the Royal Botanical Gardens in Cambridge, said: "It is very rare to grow bananas outside in this country. Mrs Millar has done fantastically well to grow so many."

Throughout the autumn and winter, the Daily Mail has highlighted plants flowering or fruiting unseasonally late, from the vine laden with grapes which grew alongside train tracks at Westcliff-on-Sea, Essex, to the seedling which produced ripe tomatoes on the central reservation of the A2 in South London.

Forecasters say the unseasonably warm weather over the last few months has fooled plants into thinking it is still late summer and acting accordingly.

"This year has been quite extraordinary in terms of the UK temperature, with several records being broken," said a spokesman for the Met Office. "In England it is going to be the warmest year, and it is certainly possible that 2007 could be even warmer.

"If you add all things together, it leads to the inescapable conclusion that we are seeing the results of climate change, and this will undoubtedly have an impact on our flora and fauna."

Fittingly, Christmas Day was snow-free in lowland Britain, and also clear following the lifting of most of the fog which caused such disruption last week.

Temperatures were around the 3-6C mark (37-43F) in England and Wales, and closer to freezing in Scotland, with wind and rain forecast in the run-up to New Year's Eve.

And having offered its longest-ever odds on a white Christmas in London this year, bookmakers William Hill said it would take bets at 50/1 on there not being one until the middle of the century.

A spokesman added that global warming could see the whole notion of snow on Christmas Day "consigned to the history books".